// Copyright (C) 2003--2004 Samy Bengio (bengio@idiap.ch)
//                
// This file is part of Torch 3.1.
//
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
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//    derived from this software without specific prior written permission.
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#include "TableLookupDistribution.h"

namespace Torch {

TableLookupDistribution::TableLookupDistribution(int column_, bool apply_log_, real prior_) : Distribution(column_+1,0)
{
  column = column_;
  apply_log = apply_log_;
  prior = prior_;
  if (!apply_log)
    prior = log(prior);
}

real TableLookupDistribution::frameLogProbability(int t, real *inputs)
{
  real lp = inputs[column];
  if (apply_log) 
    lp = log(lp / prior) ;
  else
    lp -= prior;
  log_probabilities->frames[t][0] = lp;
  return lp;
}

TableLookupDistribution::~TableLookupDistribution()
{
}

}

